/*
 * Copyright (C) 2008 TranceCode Software
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
 *
 * $Id$
 */
package org.trancecode.rdf.base;

import org.trancecode.core.AbstractImmutableHashCodeObject;
import org.trancecode.rdf.Reference;
import org.trancecode.rdf.Triple;
import org.trancecode.rdf.UriReference;
import org.trancecode.rdf.Value;

import com.google.common.base.Preconditions;


/**
 * @author Herve Quiroz
 * @version $Revision: 3842 $
 */
public final class ImmutableTriple extends AbstractImmutableHashCodeObject implements Triple
{
	private final UriReference reference;
	private final Reference subject;
	private final UriReference predicate;
	private final Value object;


	public ImmutableTriple(
		final UriReference reference, final Reference subject, final UriReference predicate, final Value object)
	{
		super(reference, subject, predicate, object);
		Preconditions.checkNotNull(reference);
		Preconditions.checkNotNull(subject);
		Preconditions.checkNotNull(predicate);
		Preconditions.checkNotNull(object);
		this.reference = reference;
		this.subject = subject;
		this.predicate = predicate;
		this.object = object;
	}


	@Override
	public Value object()
	{
		return object;
	}


	@Override
	public UriReference predicate()
	{
		return predicate;
	}


	@Override
	public UriReference reference()
	{
		return reference;
	}


	@Override
	public Reference subject()
	{
		return subject;
	}

}
